JP2003054907A - Hydrogen producing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably cool a reformed gas in a hydrogen producing apparatus. SOLUTION: This apparatus for producing a hydrogen enriched gas by reforming a raw material such as alcohol is constituted as follows. A cooler 30 is provided between a reforming part 20 and a shift part 40 to cool a high temperature reformed gas produced in the reforming part 20. The cooling is performed by jetting water to a flow passage 31 for the reformed gas by an injector 33. Because all of the water jetted as fine liquid drops is immediately evaporated, good correlation is kept between the jetting quantity and the cooling quantity. Thus, the cooling accuracy is improved. Further, the quantity of steam produced in the cooler 30 is stabilized, so the steam can be stably supplied to the reforming part 20.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a hydrogen generator for producing a hydrogen-rich gas from a predetermined raw material containing hydrogen.

[0002]

2. Description of the Related Art In recent years, fuel cells, which generate electricity by an electrochemical reaction of hydrogen and air, have been attracting attention as an energy source. Hydrogen serving as a fuel for the fuel cell is generated, for example, by reforming a predetermined raw material. As a raw material for reforming, gasoline, natural gas and other hydrocarbons, alcohols, ethers, aldehydes and the like are generally used. As a reaction for obtaining hydrogen from a raw material, a reforming reaction for obtaining a reformed gas containing hydrogen from the raw material and air or steam is known. The former is sometimes called partial oxidation and the latter is sometimes called steam reforming. The reformed gas also includes carbon monoxide and carbon dioxide that are produced in association with this reaction. A shift reaction for producing hydrogen and dioxide from carbon monoxide and water vapor may be used in combination with the reforming reaction. The shift reaction is often used together when gasoline, natural gas or other hydrocarbons are used as a raw material.

The reforming reaction is generally carried out at a high temperature of 500 to 700 ° C., while the shift reaction is 200 to 25 ° C.
It is performed at about 0 ° C. Therefore, in order to use both reactions together, it is necessary to cool the reformed gas to a temperature suitable for the shift reaction. In order to realize efficient cooling, cooling by vaporization of water as a refrigerant, that is, cooling using latent heat of water has been proposed.

[0004]

However, stable control of cooling utilizing latent heat has been extremely difficult. The cooling water supplied to the heating body is vaporized with violent pulsation, as is empirically imagined from a phenomenon when water is spilled on a heated iron plate. Further, a phenomenon called Leidenfrost phenomenon occurs in which the cooling water slides on the surface of the heating body as if the surface of the heating body is water repellent. Due to these factors, the vaporization amount of the cooling water becomes very unstable, so that stable temperature control cannot be performed.

In addition, unstable vaporization has a bad effect on the use of water vapor. For example, consider the case where steam generated by cooling is used for steam reforming. In steam reforming, it has been confirmed that carbon is precipitated when steam is insufficient for the raw material. When the vaporization of the cooling water is unstable, there is a problem that water vapor is insufficient and carbon is likely to be precipitated.

Here, the problem has been described by taking the cooling of the reformed gas as an example, but a part thereof is common to the general cooling using the liquid refrigerant. The present invention has been made to solve these problems, and an object of the present invention is to improve the accuracy of temperature control of cooling using latent heat of a liquid refrigerant. Also,
The purpose of the hydrogen generator is to effectively utilize the steam generated during cooling.

[0007]

Means for Solving the Problems and Their Actions / Effects In order to solve at least some of the above problems, the present invention provides a hydrogen generator that reforms a predetermined raw material to generate a hydrogen-rich gas, The reforming section and the cooling mechanism are provided. The reforming section is a reactor that reforms the raw material. As the raw material, for example, gasoline, natural gas and other hydrocarbons, alcohol, ether, aldehyde and the like can be used. Examples of the reforming reaction include partial oxidation of the raw material and steam reforming. It is also possible to use an autothermal type in which both are used in combination.

Various configurations can be applied to the cooling mechanism as the first configuration. As a first configuration, an injector for injecting a liquid refrigerant onto the outer surface of the flow path of the reformed gas, and a control unit for controlling the temperature of the reformed gas by the injection amount of the liquid refrigerant are provided. The flow path means a structure through which the reformed gas flows, and includes not only simple pipes but also a reaction part using the reformed gas. The liquid refrigerant can be appropriately selected according to the temperature of the reformed gas, the target temperature after cooling, and the like. Various types of injectors can be applied, and for example, an injector that can control the injection amount by electromagnetically adjusting the opening / closing duty can be used. In this specification, jetting means spraying a liquid refrigerant in the form of fine liquid droplets, and also includes jetting of a very fine liquid, that is, spraying. The control unit controls the injection amount from the injector so that the temperature of the reformed gas becomes the target temperature. The control method may be either closed loop control or open loop control. As the former, for example, feedback control based on the temperature of the reformed gas after cooling can be considered. As the latter, feedforward control based on the load of the reformer, the temperature of the reforming section, and the like can be considered. The closed loop control and the open loop control may be used together.

According to the hydrogen generator of the present invention, the reformed gas can be cooled by injecting the liquid refrigerant. The liquid refrigerant immediately evaporates by being atomized and sprayed on the flow path. Therefore, it is possible to maintain a good correlation between the amount of heat taken from the flow path by cooling, that is, the cooling amount and the injection amount, and it is possible to perform stable and accurate cooling. Further, since vaporization occurs immediately after the injection, there is also an advantage that the response of cooling is improved.

As a second configuration in place of the above-described first configuration, the cooling mechanism covers at least a part of the reformed gas flow path with a permeation section through which the liquid refrigerant can permeate, and the permeation section is covered with the liquid refrigerant. Can also be adopted. The penetration part is
For example, a wick such as a net, a sintered metal, a porous body, or a groove can be applied. The temperature can be controlled by the amount of liquid refrigerant supplied to the permeation section. Various supply methods can be used for the liquid refrigerant, and the liquid refrigerant may be injected as in the first configuration.

According to the second structure, since the liquid refrigerant permeates the permeating portion, it is possible to efficiently cool the portion where the liquid refrigerant is difficult to jet. In addition, since the liquid refrigerant is in the same state as being miniaturized in the permeation section, it is possible to improve the vaporization response and stabilize the vaporization amount, as in the first configuration.

Regardless of which of the first configuration and the second configuration is applied to the cooling mechanism, the hydrogen generating apparatus of the present invention can be applied with various configurations described below. .

For example, when water can be used as a liquid refrigerant and the reforming section reaction includes steam reforming, a steam supply mechanism for supplying the steam generated by the cooling mechanism to the reforming section is used. It is desirable to prepare. By doing so, the steam generated by cooling can be effectively utilized in the reforming reaction. In the present invention, since the amount of steam generated in the cooling mechanism is stable, the amount of steam suitable for the reforming reaction can be stably secured. Therefore, it is possible to suppress the harmful effects such as carbon deposition due to insufficient steam.

In the present invention, it is also desirable to provide the cooling mechanism with a pressure chamber for supplying water as a liquid refrigerant. This pressure chamber can be configured to include a supply port for supplying the liquid refrigerant to the cooling mechanism, and a pressure maintaining valve for discharging water when the internal pressure is equal to or higher than a predetermined value, separately from the supply port. By doing so, the supply amount of the liquid refrigerant to the cooling mechanism can be more stabilized.

When the pressure chamber is provided, it is desirable that the water discharged from the pressure holding valve is also supplied to the reforming section by the steam supply mechanism. By doing so, the water discharged from the pressure holding valve can also be effectively utilized in the reforming reaction.

Further, in such a structure, an adjusting mechanism capable of adjusting the amount of water supplied to the pressure chamber is provided, and both the amount of water supplied to the cooling mechanism and the amount of water supplied to the pressure chamber are controlled. Is desirable. The former can be performed from the viewpoint of temperature control. The latter can be controlled based on the amount of steam required in the reforming section. By doing so, it is possible to satisfy both the requirement regarding the cooling of the reformed gas and the requirement regarding the reaction amount of the reforming.

INDUSTRIAL APPLICABILITY The present invention is highly useful in a hydrogen generator equipped with a shift section downstream of the reforming section when at least a part of the cooling mechanism is provided between the reforming section and the shift section. The shift section refers to a reactor that performs a shift reaction in which hydrogen and carbon dioxide are produced from carbon monoxide and steam in the reformed gas. Generally, the reaction temperature of the shift section is lower than that of the reforming section, so that the reformed gas needs to be cooled promptly and accurately. According to the present invention, it is possible to perform cooling that meets such requirements.

In the above description, the cooling mechanism has been described as cooling the flow path of the reformed gas, but in addition, the cooling mechanism may cool the reforming portion, the shift portion and the like. It is also possible to cool the consumption system of the generated hydrogen such as a fuel cell. The present invention can be configured as a hydrogen generation method, a cooling control method in the hydrogen generation apparatus, and the like, in addition to the above-described hydrogen generation apparatus. Further, regardless of the hydrogen generator, it is also possible to configure in the form of a cooling device for cooling a general heating body.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION A. First Embodiment: FIG. 1 is an explanatory diagram showing a schematic configuration of a fuel cell system as a first embodiment. This system uses a fuel cell 60 as a hydrogen consumption system.
And a hydrogen generator that generates hydrogen by reforming the raw material. The fuel cell 60 is a device that generates electricity by an electrochemical reaction between oxygen in the air supplied to the oxygen electrode 61 and hydrogen supplied to the hydrogen electrode 62. Fuel cell 60
Although various types can be used, in this example, the solid polymer electrolyte membrane type was used.

As the raw material for producing hydrogen, for example, gasoline, natural gas or other hydrocarbon, alcohol, ether, aldehyde, etc. can be used.
In this embodiment, city gas containing natural gas as a main component is used as a raw material. These raw materials are supplied to the heating unit 10 together with water and heated to a temperature suitable for reforming. In this embodiment, the temperature is raised to about 500 to 700 ° C. The heated raw material and the like are supplied to the reforming unit 20. The amounts of the raw material and water supplied to the heating unit 10 are adjusted so that the ratio of the water and the raw material supplied to the reforming unit 20 is about 3.

The heating unit 10 is a reactor for steam reforming the raw material. Steam reforming is an endothermic reaction that produces a reformed gas containing hydrogen from a raw material and water. In addition to this reaction, carbon monoxide and carbon dioxide are also produced. The reforming section 20 carries a catalyst suitable for this reaction. The catalyst is
It can be selected according to the type of raw material, for example, platinum,
Noble metal catalysts such as ruthenium and rhodium, copper-zinc system,
A base metal catalyst such as an iron-chromium system can be used.
The reforming unit 20 may be of an autothermal type that performs partial oxidation reaction in combination with steam reforming. What is a partial oxidation reaction?
An exothermic reaction that produces a reformed gas containing hydrogen from a raw material and oxygen. In addition to this reaction, carbon monoxide and carbon dioxide are also produced. By using steam reforming and partial oxidation reaction together, heat applied from the outside can be suppressed.

The high-temperature reformed gas generated in the reforming section 20 is supplied to the shift section 40 via the cooler 30. The shift unit 40 is a reactor that causes a shift reaction to generate hydrogen and carbon dioxide from carbon monoxide and water in the reformed gas. The shift section 40 carries a catalyst suitable for this reaction. A catalyst similar to that used in the reforming section 20 can be applied.

A CO oxidation unit 50 is provided downstream of the shift unit 40.
Is provided. The CO oxidation unit 50 is a reactor that selectively oxidizes untreated carbon monoxide in the shift unit 40.
The CO oxidation part 50 carries a catalyst suitable for this reaction. A catalyst similar to that used in the reforming section can be applied.

The reaction temperature of the reforming section 20 is 500 to 700 ° C.
On the other hand, the reaction temperature of the shift section 40 is 200 to
It is about 250 ° C. The shift reaction is an equilibrium reaction,
At high temperatures, the concentration of carbon monoxide increases. For example, it is known that the concentration of carbon monoxide is about 8% at about 700 ° C. On the other hand, at about 250 ° C, about 0.5
Drastically reduced to%. It is preferable that the CO oxidation unit 50 also has a reaction temperature of about 200 ° C. It is known that, in a higher temperature environment than this, not only carbon monoxide but also hydrogen in the reformed gas is oxidized at a high ratio.

The cooler 30 is a mechanism for cooling the reformed gas to about 200 ° C. for the above reason. Cooler 3
In No. 0, an injection chamber 32 for injecting water as a refrigerant is provided around the flow path 31 through which the reformed gas passes. In this embodiment, the injection chamber 32 and the flow passage 31 are separated by a wall so that the water injected into the injection chamber does not mix into the flow passage 31. The water droplets injected into the injection chamber immediately vaporize. This steam is supplied to the heating unit 10 through a pipe connected to the injection chamber 32 and used for the reforming reaction.

Injection into the injection chamber is performed by a plurality of injectors 3.
It starts from 3. The water is pressurized and supplied to each injector 33 by the pump 34, and the injection amount can be controlled by electromagnetically controlling the opening / closing duty of the injector 33.

The supply amount of water from the pump 34 and the injection amount of the injector 33 are controlled by the control unit 70. The control unit 70 is a microcomputer having a CPU, a memory, etc. inside, and executes each control by software. Of course, these controls may be executed by hardware by a dedicated control circuit.

Feedback control based on the temperature of the reformed gas can be applied to control the amount of water supplied and the amount of water injected. In order to realize such control, the control unit 7
A signal from the temperature sensor 71 that detects the temperature of the reformed gas is input to 0. Furthermore, in order to improve the followability to the load fluctuation of the fuel cell system, a combination of feedforward control for estimating the amount of heat to be taken by cooling, that is, the cooling amount, based on the load of the reforming unit and the temperature of the reforming unit, etc. Is desirable. The injection amount is, for example, the injection chamber 32.
It is assumed that all of the water sprayed to is vaporized, and the latent heat for that is set to match the required cooling amount.

According to the hydrogen generator of the first embodiment described above, the reformed gas can be efficiently cooled by utilizing the spray of water. This is because the injected water can be immediately vaporized by forming fine water droplets by the injector 33. Since the amount of water vaporized does not pulsate, the amount of cooling can be stabilized. In addition, since the gas is immediately vaporized, the cooling response can be improved and the cooling accuracy can be improved.

According to the configuration of the first embodiment, the temperature of the reformed gas is controlled to 200 ° C., and as a result, the outlet temperature of the shift section 40 can be suppressed to about 225 ° C. As a result, it was possible to drastically reduce the concentration of carbon monoxide from the value of 8% obtained without sufficient cooling to 0.4%. Finally, at the outlet of the CO oxidation unit 50, the composition of gas is as follows: hydrogen 63%, carbon dioxide 16.5%, nitrogen 2.6%, water vapor 17.9.
% And carbon monoxide 3 ppm.

In the first embodiment, as a result of stable vaporization of water, the amount of steam produced is also stable. Injector 3
Since the amount of water sprayed from No. 3 and the amount of generated steam maintain a good correlation, there is also an advantage that the generated steam can be stably supplied to the reforming section 20. As a result, in the reforming section 20, precipitation of carbon due to insufficient steam is suppressed.

In the first embodiment, the steam generated in the injection chamber 32 is used for reforming, but it may be used for other purposes or discarded.

B. Second Embodiment: FIG. 2 is an explanatory diagram showing a schematic configuration of a fuel cell system as a second embodiment. The structure of the water supply system to the cooler differs from that of the first embodiment.
Other configurations are similar to those of the first embodiment, and therefore only different points will be described.

In the second embodiment, the water discharged from the pump 34 is supplied to the injector 33 via the pressure chamber 35. The discharge pressure of the pump 34 is sufficiently higher than the internal pressure of the pressure chamber 35. A pressure holding valve 36 is provided in the pressure chamber 35. If the internal pressure exceeds the specified value, the pressure holding valve 36
Is opened and water is discharged from the pressure chamber 35. The discharged water is heated by the heating unit 1 together with the steam generated in the injection chamber 32.
0 and is used for reforming.

The control unit 70A is a microcomputer similar to that of the first embodiment, and controls the supply amount from the pump 34 and the injection amount from the injector 33. In the first embodiment, the supply amount and the like are controlled in consideration of cooling of the reformed gas, whereas in the second embodiment, control is performed in consideration of cooling and supply of steam to the reforming section 20. Is different. That is, the control unit 70A controls the injection amount based on the amount of water required for cooling, and controls the supply amount from the pump 34 based on the supply amount of steam to the reforming section 20. Such control is realized by the flowchart shown below.

FIG. 3 is a flowchart of the water supply amount control process. This is a process executed by the control unit 70A. When this process is started, the control unit 70A inputs the required hydrogen amount (step S10), and based on this, the water supply amount W1 required to secure the amount of steam necessary for reforming.
Is set (step S12). The relationship between the required hydrogen amount and the water supply amount W1 may be specified in advance by experiments or analysis.

Next, the control unit 70A inputs the temperature of the reformed gas (step S14), and the amount of water W required for cooling is W.
2 is set (step S16). The water amount W2 can be set based on the difference between the temperature of the reformed gas and the target temperature. As with the first embodiment, feedforward control that considers factors such as the required hydrogen amount and the temperature of the reforming section 20 may be combined to set the water amount W2.

The control unit 70A controls the drive of the pump 34 so as to secure the larger one of the two flow rates W1 and W2 thus set (step S18). By doing so, it becomes possible to cover the required flow rates W1 and W2 without deficiency. On the other hand, the injector 33 is duty-controlled so as to inject the water amount W2 required for cooling (step S20).

When the water supply amount W1 required for reforming is less than the water amount W2 required for cooling, the water amount W2 required for cooling is supplied from the pump 34. Therefore, after all the supplied water is injected by the injector 33 and vaporized,
It is supplied to the reforming section 20.

On the other hand, when the water supply amount W1 required for reforming exceeds the water amount W2 required for cooling, the water supply amount W1 required for reforming is supplied from the pump 34. Therefore, only a part of the supplied water is injected by the injector 33. The remaining water that is not jetted acts to raise the internal pressure of the pressure chamber 35, so the pressure holding valve 36 is opened. As a result, part of the water supplied from the pump 34 is vaporized in the injection chamber 32, and the rest leaks from the pressure holding valve 36 and is supplied to the reforming section 20. Therefore, the water supply amount W1 required for reforming is secured as set.

According to the second embodiment, in addition to the effects of the first embodiment, it is possible to achieve both temperature control and control of the amount of water required for reforming. Therefore, the reforming reaction can be stably generated, the required hydrogen amount can be accurately generated, and the carbon deposition due to the insufficient amount of water vapor can be further suppressed. Further, in the second embodiment, by providing the pressure chamber 35, it is possible to stabilize the supply pressure to the injector 33, and there is an advantage that the accuracy and response of injection control can be improved.

C. Third Embodiment: FIG. 4 is a sectional view showing a schematic configuration of a cooler as a third embodiment. The configuration applicable instead of the cooler 30 in the first embodiment (FIG. 1) has been illustrated.

The cooler 130 as the third embodiment is similar to the first embodiment in that it includes a reformed gas passage 131, a spray chamber 132 and an injector 133. The third embodiment differs from the first embodiment in that the permeation member 134 is arranged along the wall that divides the flow path 131 and the spray chamber 132. The permeation member 134 is a member into which the ejected liquid permeates due to surface tension. For example, a wire mesh, a sintered metal, a porous chamber body, a groove, or another wick can be applied. The pore diameter for permeation can be arbitrarily set depending on the type of the refrigerant, the injection amount, the temperature, etc. so as to ensure sufficient diffusivity.

According to the cooler 130 of the third embodiment, the permeating member 134 allows the refrigerant to be diffused in a wide range, so that efficient cooling can be performed. In addition, since the dripping of the refrigerant can be suppressed by the action of the permeation member 134, there is an advantage that the degree of freedom in designing the position of the injector 133, the injection direction, and the like is improved.

In the process of permeating the pores of the permeation member 134,
Since the refrigerant can be miniaturized, the refrigerant can be stably vaporized with high responsiveness as in the case of injection. Therefore, in the third embodiment, the case of injecting the refrigerant has been illustrated, but it is not always necessary to supply the refrigerant in the form of fine liquid.

By providing the permeation member 134, it is possible to cool the portion where it is difficult to inject the refrigerant. FIG. 5 is a sectional perspective view showing the structure of a cooling machine as a modified example. The internal structure when cut along the plane of symmetry is shown by a perspective view. In addition, a plan view of the AA cross section is shown below in order to help grasp the shape.

The cooling machine 230 of the modification is constructed as a so-called tube-fin type heat exchanger. A tube 236 having a circular cross section is provided for heat exchange in the flow path 231 of the reformed gas to be cooled. This tube 2
A heat exchange fin 232 having a circular cross section is attached to 36. As shown in the drawing, the reformed gas is sewn between the heat exchange fins 232 and cooled.

On the inner surface of the tube 236 and the upper surface of the flow path 231, the permeation member 234 similar to that described in FIG. 4 is provided. From the injector 233 to the injection chamber 235
The water sprayed onto the permeation member 234 permeates the permeation member 234 and reaches the upper surface of the flow path 231 and the inner surface of the tube 236.
As a result, cooling is performed at each part,
The water vaporizes. The vaporized water is discharged to the outside through the upper injection chamber 235 and the lower water vapor passage 237.

By using the permeating member, it is possible to permeate the refrigerant extensively even with the complicated shape shown in the modified example, and the cooling response and stability can be improved. In the modification, the tube-fin type cooler is illustrated, but the structure using the permeation member is also useful for various types of heat exchangers such as a laminated heat exchanger.

FIG. 6 is a sectional perspective view showing the structure of a cooling machine as a modification of the third embodiment. A perspective view shows a state of being cut along a plane of symmetry. Illustration of the injector is omitted.

The cooling machine 430 of the modified example is realized by a tube type heat exchanger using an infiltration member with an integral structure. As shown in the figure, a hole 437 for heat exchange penetrates through the main body 431 having a reformed gas flow path formed of a honeycomb. The permeation member 434 is joined to the inner surface of the hole 437 and one surface of the main body. The injection of water is performed on the surface provided with the permeation member (the upper surface in the figure).

With this structure, the same cooling as that of the third embodiment can be realized. In a modification, the same catalyst as the CO oxidation part and the shift part may be supported on the honeycomb. By doing so, it is also possible to configure as a mechanism for cooling the reactor. According to such a configuration, the efficiency of the catalyst can be improved by efficiently performing the cooling, and the size of the entire apparatus can be reduced to about 1/3.

D. Fourth Embodiment: FIG. 7 is a cross-sectional perspective view showing the structure of a cooler as a fourth embodiment. The internal structure cut along the plane of symmetry is shown in a perspective view.

The cooler 330 of the fourth embodiment is a tube
It is configured as a fin type heat exchanger. As described in the modification (FIG. 5), the reformed gas passage 331 is provided with the tube 337 having fins for heat exchange. The cooler 330 is different from the modification (FIG. 5),
No permeation member is provided on the inner surface of the tube 337 and the upper surface of the flow path 331. Instead of tube 737
Are filled with a heating medium for transporting heat. As the heat medium, water, oil or the like can be used,
It is preferable to select a substance that does not boil easily. The heat exchange chamber 33 is provided between the upper surface of the flow path 331 and the injection chamber 335.
6 is provided. It is preferable that the inside is vacuumed or filled with an inert gas. A penetrating member 334 is provided between the injection chamber 335 and the heat exchange chamber 336.

The water sprayed from the injector 333 is
It permeates the permeation member 334, cools the heat exchange chamber 336, and indirectly cools the heat medium of the tube 737. The reformed gas is cooled by exchanging heat with the heat medium via the fins.

According to the fourth embodiment, by filling the inside of the tube 737 with the heat medium, it functions as a heat siphon or a heat pipe, and it is possible to make the overall temperature uniform.

In the configuration of the fourth embodiment, the reformed gas passage 3
A catalyst can be supported on 31. The shift section and the CO oxidation section may need to be cooled during the reaction, and the cooler 330 of the fourth embodiment can be configured as these reactors by supporting a catalyst. According to the configuration of the fourth embodiment, the temperature in the reactor can be made uniform, the catalyst can be used uniformly, and the reaction can be stabilized. Furthermore,
Based on these effects, there is also an advantage that the reactor can be downsized.

Also in the fourth embodiment, since the permeating member is used, the case of injecting the refrigerant has been illustrated, but it is not always necessary to supply it as a fine liquid. On the contrary, in the case where the water is sprayed by atomizing, it is possible to adopt a configuration in which the penetrating member is omitted in the fourth embodiment.

FIG. 8 is a sectional view of a cooling machine as a modification of the fourth embodiment. The case where it is configured as a so-called drone cup laminated type heat exchanger will be exemplified. Such a structure has an advantage that mass production is possible by pressing and brazing. Although the modified example can be configured as a single cooling device, here, a case where it is configured as a cooling mechanism for the CO oxidation unit will be described.

The cooler 530 has a honeycomb 531 that serves as a flow path for the reformed gas and also serves as a reaction portion for the CO oxidation reaction. A catalyst suitable for the CO oxidation reaction is carried on the honeycomb 531 and the reaction occurs when the reformed gas flows in a direction penetrating the paper surface.

The periphery of the honeycomb 531 is filled with a heat medium such as water or oil. The upper part of the heat medium is initially in a vacuum state, and when the CO oxidation reaction starts, it is filled with the vapor of the heat medium. This steam flows in the direction of the arrow through the circulation path 534 shown in the figure. The injection chamber 53 is provided above the circulation path 534.
2 is provided, and water is injected from the injector 533. The vapor of the heat medium is cooled here, and is liquefied again to cool the honeycomb 531.

The injection amount from the injector is the honeycomb 5
Although it is possible to perform control based on the temperature of 31, the temperature of the gas discharged from here, etc., in the modified example, the internal pressure of the circulation path 534 is used as a parameter related to these temperatures. As shown, circuit 53
4 is provided with a pressure sensor 535, which controls the pressure detected here to a target value. When the pressure is high, it means that evaporation of heat is severe, that is, cooling is insufficient, so that the injection amount is increased.
In the opposite case, the injection amount is reduced. In this example, by controlling the pressure to 200 KPa, for example, the heat doubling part could be made uniform at about 120 ° C. The fact that various parameters related to the temperature can be applied to the control of the injection amount is the same in the other embodiments.

E. Fifth Embodiment: FIG. 9 is an explanatory diagram showing a schematic configuration of a hydrogen generator as a fifth embodiment. In the configuration of the second embodiment (FIG. 2), only the configuration between the reforming section 20 and the CO oxidation section 50 is shown. In addition, the control unit 7
Illustration of 0 is omitted. The configuration of the part not shown in FIG. 9 is similar to that of the second embodiment (FIG. 2).

The fifth embodiment differs from the second embodiment in that the shift portion is provided separately for the high temperature shift portion 80 and the low temperature shift portion 90. The high temperature shift unit 80 is 200-
It is a reactor that performs a shift reaction at a reaction temperature of 450 ° C.
The low temperature shift section 90 is a reactor that performs a shift reaction at about 200 ° C. Both of them carry a catalyst suitable for each reaction. For example, an iron-chromium catalyst can be applied to the high temperature shift section 80. For example, a copper-zinc catalyst can be applied to the low temperature shift section.

The high temperature shift section 80 and the low temperature shift section 90 are provided with injection chambers 82 and 92 along the reformed gas flow paths 81 and 91, respectively. Water can be injected from the injectors 83 and 93 into this injection chamber. This cooling mechanism has the same configuration as the cooler 30.

Water is supplied in parallel from the pressure chamber 35 to the injectors 33, 83 and 93 of the cooler 30, the high temperature shift section 80 and the low temperature shift section 90. In addition, each injection chamber 32,
The steam generated in 82, 92 merges and is supplied to the heating unit. As in the second embodiment, the pressure holding valve 36 of the pressure chamber 35
The water discharged from the tank is also merged and supplied to the heating unit.

The cooler 30 shown in the second embodiment can be applied to a reactor as shown in FIG. 9, and a plurality of coolers can be provided in parallel. By doing so, it is possible to individually control the temperature of the reformed gas discharged from the reforming section 20 and the temperature of each reactor with high accuracy and high response. Further, by providing the pressure chamber 35 and the pressure-holding valve 36, it is possible to achieve both the amount of water necessary for the reaction and the temperature control, as in the second embodiment.

According to the fifth embodiment, by improving the accuracy of temperature control of each reactor, the utilization rate of the catalyst in each reactor can be improved, and the reactor can be downsized. There is also. In the configuration of the fifth embodiment, the volume of the high temperature shift section 80 and the volume of the low temperature shift section 90 are each halved.
The volume of the entire device can be reduced to about 2/3.

In the fifth embodiment, the case where the cooling mechanism of the embodiment is applied to the shift portion is illustrated. The cooling mechanism of the embodiment is
The present invention can be applied not only to this structure but also to various structures. As an example, consider application to a hydrogen generator using alcohol such as methanol as a raw material. In general, when alcohol is used as a raw material, the shift portion is often omitted because the amount of carbon monoxide produced is relatively small. For example, in the configuration of the first embodiment (FIG. 1), the reformed gas generated in the reforming section 20 is supplied to the CO oxidation section 50 via the cooler 30. In this case, the cooler 30 may be further omitted and the CO oxidation unit 50 may be provided with a cooling mechanism like the high temperature shift unit 80 in FIG. 9.

Although various embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to these embodiments and that various configurations can be adopted without departing from the spirit of the invention. In the embodiment, the application example as the cooler of the fuel cell system is shown, but the present embodiment is not limited to such a case, and can be applied to cooling various heating bodies.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a fuel cell system as a first embodiment.

FIG. 2 is an explanatory diagram showing a schematic configuration of a fuel cell system as a second embodiment.

FIG. 3 is a flowchart of a water supply amount control process.

FIG. 4 is a sectional view showing a schematic configuration of a cooling machine as a third embodiment.

FIG. 5 is a cross-sectional perspective view showing the structure of a cooling machine as a modified example.

FIG. 6 is a sectional perspective view showing the structure of a cooling machine as a modified example of the third embodiment.

FIG. 7 is a sectional perspective view showing the structure of a cooling machine as a fourth embodiment.

FIG. 8 is a sectional view of a cooling machine as a modified example of the fourth embodiment.

FIG. 9 is an explanatory diagram showing a schematic configuration of a hydrogen generator as a fifth embodiment.

[Explanation of symbols]

10 ... Heating part 20 ... reforming section 30 ... Cooler 31 ... Channel 32 ... Injection chamber 33 ... Injector 34 ... Pump 35 ... Pressure chamber 36 ... Pressure holding valve 40 ... shift part 50 ... CO oxidation part 60 ... Fuel cell 61 ... oxygen pole 62 ... Hydrogen electrode 70, 70A ... Control unit 71 ... Temperature sensor 80 ... High temperature shift section 90 ... Low temperature shift section 81, 91 ... Channel 82, 92 ... Injection chamber 83, 93 ... Injector 130 ... Cooler 131 ... Channel 132 ... Spraying chamber 133 ... Injector 134 ... Penetration member 230 ... Cooler 231 ... Flow path 232 ... Heat exchange fin 233 ... Injector 234 ... Penetration member 235 ... Injection chamber 236 ... tube 237 ... Water vapor flow path 330 ... Cooler 331 ... Flow path 333 ... Injector 334 ... Penetration member 335 ... Injection chamber 336 ... Heat exchange room 337 ... Tube 430 ... Cooler 431 ... Main body 434 ... Penetration member 437 ... hole 530 ... Cooler 531 ... Honeycomb 532 ... Injection chamber 533 ... Injector 534 ... Circulation path 535 ... Pressure sensor 737 ... tube

Claims (9)

[Claims] 1. A hydrogen generator for generating a hydrogen-rich gas by reforming a predetermined raw material, the reforming section performing the reforming, and cooling the reformed gas discharged from the reforming section. A cooling mechanism, wherein the cooling mechanism controls the temperature of the reformed gas by an injector for injecting a liquid refrigerant onto the outer surface of the flow path of the reformed gas, and the injection amount of the liquid refrigerant. And a hydrogen generator comprising. 2. A hydrogen generator for generating a hydrogen-rich gas by reforming a predetermined raw material, the reforming section performing the reforming, and cooling the reformed gas discharged from the reforming section. A cooling mechanism, the cooling mechanism covering at least a part of the flow path of the reformed gas, a permeation section capable of permeating a liquid refrigerant, and a supply section supplying the liquid refrigerant to the permeation section. A cooling unit that controls the temperature of the reformed gas according to the supply amount of the liquid refrigerant. 3. The hydrogen generator according to claim 1 or 2, wherein the liquid refrigerant is water, and reforming in the reforming unit includes steam reforming, which is generated by the cooling mechanism. A hydrogen generator comprising a steam supply mechanism for supplying steam to the reforming section. 4. The hydrogen generator according to claim 3, further comprising a pressure chamber for supplying water as the liquid refrigerant to the cooling mechanism, the pressure chamber supplying the liquid refrigerant to the cooling mechanism. A hydrogen generator comprising: a supply port for supplying water and a pressure-holding valve that discharges water when the internal pressure exceeds a predetermined value, separately from the supply port. 5. The hydrogen generator according to claim 4, wherein the water vapor supply mechanism supplies the water discharged from the pressure maintaining valve together to the reforming section. 6. The hydrogen generator according to claim 5, further comprising an adjusting mechanism capable of adjusting the amount of water supplied to the pressure chamber, wherein the control unit controls the temperature, and further improves the temperature. A hydrogen generator that controls the amount of water supplied to the pressure chamber based on the amount of water vapor required in the quality part. 7. The hydrogen generator according to claim 1 or 2, wherein a shift reaction for generating hydrogen and carbon dioxide from carbon monoxide and steam in the reformed gas is provided downstream of the reforming section. A hydrogen generator comprising a shift unit for performing, and at least a part of the cooling mechanism is provided between the reforming unit and the shift unit. 8. A cooling device for liquid-cooling a heating body, comprising: an injector for injecting a liquid refrigerant onto the heating body; and a control section for controlling the temperature of the heating body according to an injection amount of the liquid refrigerant. Cooling system. 9. A cooling device for liquid-cooling a heating element, the at least part of the heating element being covered, a permeation section through which a liquid refrigerant can permeate, and a supply for supplying the liquid refrigerant to the permeation section. And a control unit that controls the temperature of the heating element according to the supply amount of the liquid refrigerant.